When we talk about character, we imagine people who are real to themselves and to others. We see people who do just what they say they will do, exactly when they said they would do it, with the agreed conditions followed to the letter. Such people are the ones worthy of leadership. They are the individuals whom all others around turn to for guidance simply because over time they have demonstrated that they know what they're doing, and that they keep their word. Hence they can be trusted and entrusted with serious things.
Dependability, like any other trait, is a habit. Thus simply means it's continual until learnt. If you learn to respect yourself and keep to principles and commitments even when it gets inconvenient for you to do so, you will earn the respect of the people around you in no time at all.
To do this, you need to start now. Start by inculcating the dependability habit in you. Let others know they can rely on you and hope for you to deliver. Let them leave entrust treasures to your keep and worry less about it because they know you're capable of keeping it safe.
If you procrastinate often, you might want to start small. Developing this habit takes time and effort, so be sure to have enough of that to pull you through. Time keeping is a good place to start. Promise yourself that you would keep to time first, and a lot other things might start falling in place easily.
Show character by dependability.